This application is for a P30 Center for Drug Abuse Prevention in the Child Welfare System (CDAP-CWS). The Center would continue support for an infrastructure that was originally created through a NIDA P20 mechanism for the systematic integration and extension of work aimed at CWS science, practice, and policy. The proposed Center aims to accomplish the following: (a) further specify conceptual models to inform the development of interventions relevant to CWS children and families, (b) increase the implementation of evidence-based interventions into routine CWS practice, with the ultimate goal of (c) reducing the incidence of drug abuse and related problems in CWS populations. Two cores will comprise the Center. The Administrative Core will provide shared resources, leadership, and oversight to integrate and extend knowledge from our current, previous, and planned CWS studies; facilitate collaborations with CWS researchers to disseminate key findings to academic and social policy communities; support 7-10 pilot studies; and facilitate the professional development of early career scientists. The Capacity Enhancement Core will provide the infrastructure to incorporate new key areas related to CWS drug abuse prevention into our current and future studies through activities in three areas: calculating the costs and immediate benefits of evidence-based interventions in the CWS on placement outcomes, improving our ability to implement drug abuse preventive interventions that are informed by or incorporate biosocial measures and methods of stress neurobiology and genetics, and facilitating our understanding of the role of fathers, drug abuse, and child outcomes in CWS families. The proposed work includes 11 multidisciplinary scientists (including 5 early career investigators) and will utilize our base of 32 federally funded projects. The two cores will work synergistically and provide shared resources among current and future projects to inform specific interventions aimed at preventing drug abuse in CWS families.